Rook Corvus frugilegus 秃鼻烏鴉
Category I. Accidental.
IDENTIFICATION
Nov. 2017, Michelle and Peter Wong. First-winter.
44-46 cm. Large all black Corvid with small head, obvious crown peak and relatively thin legs. Thigh feathers shaggy, bill slender and sharp without obviously curved culmen and has pale base, though the latter can be difficult to detect on immature birds such as this, which are also duller and browner.
Nov. 2017, Michelle and Peter Wong. First-winter.
The pointed bill is usually visible in flight and the primary fingers are distinct when spread.
VOCALISATIONS
Typically, a dry, harsh, nasal ‘kraar’, flatter than most calls of Large-billed Crow.
DISTRIBUTION & HABITAT PREFERENCE
Both birds have occurred in lowland areas of fish ponds, wet agriculture and Mai Po NR.
OCCURRENCE
2017: A first-winter at Mai Po NR on 1 November (Kwok 2019) remained there and Lut Chau/Fung Lok Wai until 20 March 2018.
2018: an adult at Long Valley on 19 November; a first-winter at Lut Chau and Mai Po NR from 13 December to 11 March 2019.
BEHAVIOUR, FORAGING & DIET
No observations.
RANGE & SYSTEMATICS
The nominate taxon occurs from northwest Europe south to Spain and east through much of Europe and western Russia to Kazakhstan, western Xinjiang and northwest Mongolia, south to southeast Europe, northern parts of the Middle East, Iran, Afghanistan and Pakistan. C. f. pastinator occurs from northern and central Mongolia, eastern Siberia and Ussuriland south to Korea and northeast China. Populations in Russia, Kazakhstan, Mongolia and northeast China migrate south for winter (Madge 2020).
In China breeds in northern Xinjiang and provinces of the far northeast and is present all year in other areas of China as far south as the Yangtze, though avoiding high plateau areas in the west (Liu and Chen 2020). Densities appear to be low in much of the country.
CONSERVATION STATUS
IUCN: Least Concern. Population trend decreasing.
Kwok, C. T. (2019). Rook Corvus frugilegus at Mai Po Nature Reserve. The first Hong Kong record. Hong Kong Bird Report 2017: 261-262.
Liu, Y. and Y. H. Chen (eds) (2020). The CNG Field Guide to the Birds of China (in Chinese). Hunan Science and Technology Publication House.
Madge, S. (2020). Rook (Corvus frugilegus), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.rook1.01
